I legitimately think it's possible that a properly managed "for the profit of the investors" social media company will always follow this path.

It's why I think the right future for social media is non-profit. None of this is amazing technology anymore. This would also have the benefit that it would take the question of "how do we avoid doing harm while still making profit off the table." Could write a statement of values and intent that legitimately puts well being of users and society ahead of everything else. (Which no for-profit with externally raised capital is able to do today.)